建植第1年刈割对黑麦草+白三叶草地杂草空间格局的影响

栽培草地稳定性是近年来草地建植与管理的核心问题之一，其中草地抗杂草入侵是其稳定性的重要表现形式。本研究应用地统计学分析方法，分析了刈割处理下多年生黑麦草(Lolium perenne)+白三叶（Trifolium repens）混播草地杂草生物量空间分布的异质性。结果表明，不同刈割强度下，多年生黑麦草+白三叶混播草地入侵杂草地上生物量空间格局异质化程度及其相关范围变化比较明显。变异函数的基台值(C0+C)在不同刈割强度下的变化表明，在重度刈割条件下，杂草地上生物量空间分布异质性最高(12.530)，对照条件下次之(4.751)，轻度刈割条件下较低(4.557)，中度刈割条件下最低(3.149)。变异函数的相关范围(A0)表明，在重度刈割条件下空间相关范围最大(1 004.1 cm)，中度刈割条件下最小(122.1 cm)，轻度刈割 (161.9 cm)和对照(219.1 cm)条件下居中。空间变异比分析表明，由空间自相关因素引起的空间异质性占主要部分(50.3%～93.5%)。空间分布格局图(Kriging map)分析进一步显示，不同刈割强度下多年生黑麦草+白三叶混播草地杂草地上生物量格局变化显著。

Influence of different defoliation intensities to spatial heterogeneity of above-ground biomass of weeds in Lolium perenne +Trifolium repens pasture

Pasture stability is one of the core issues in pasture establishment and management research，and weed invasion resistance is an important problem. Spatial patterns of the above ground biomass of weed were determined using a geostatistical analysis in different defoliation intensity in Lolium perenne+Trifolium repens pasture. The results showed that the heterogeneity in spatial distribution of the above ground biomass and the distance of spatial dependence varied significantly. Under different defoliation intensity, weed biomass had the biggest value of sill (C0+C) (12.53), indicating that the distribution of the above ground biomass was not spatially heterogenous under heavy defoliation. The sill for CK was 4.751, the light defoliation intensity was 4.557, and middle defoliation intensity was 3.149.Similarly, the distance of spatial dependence also varied under different defoliation intensity. Analysis of spatial variation revealed that the spatial heterogeneity under different defoliation intensities in L.perenne+T.repens pasture as largely caused by spatial autocorrelation (50.3%～93.5%).The Krigingmap further showed a great spatial heterogeneity of the above ground biomass.